Sifting grate



May 1, 1923. 1, 53,870

J. W. HARTMANN SIFTING GRATE I Filed Oct. 14 1920 2 SheetQ-Sheet WWWINVENTOR.

jyflw ATTMNEYJ J. w. HARTMANN SIFTING IGRATE Filed Oct. 14, 1920 2Sheets-Sheet 2 INVENTOR.

' ATTORNEY Patented Mayl, 1923.

u are sf JOHN ,w. HARTMAnn; or BROOKLYN, new YORK.

SIF'IING GRATE.

Application filed October 14, 1920. Serial No. 416,925.

of New York, have invented certain new and useful Improvements in Siftng Grates,

of which the following is a specification." .The invention relates togrates for furnacesund other combustion apparatusfrom which'it isnecessaryto remove accumulations of residual substances, such as ashesand clinkers,- and the object thereof is to provide means whereby'theseresidues may be readily separatedfrom the igneous fuel withoutextinguishing the fire'ormaterially retarding co-mbustiom a V a c Thecombustion in furnaces of all types is generally very intense when thefire is new, but as the combustion proceeds the residual incombustibleearths and stones,

which are associated with the. fueLgra-dually increase invquantity andretard combustion until the attendant, with more or less difliculty,removes ,them from the combustion zone This result is usuallyattained byshaking the grate to thereby cause the ashes to; pass between the gratebars and into the ash pit of the furnace, but this shaking'op erationdoes not remove such masses of clinkers as are too large to pass betweenthe grate bars, and these masses often become so great as to necessitatethe dumping of the fire, and the kindlingof a fresh one. The intensityof the combustion is largely dependent upon the-strength' of the draft,and this is strongest when the fuel 1s first laid, since at that timethe fuel has not been compacted,-and the interstices have not becomefilled with the :incombustible residues which later obstruct the draftand lessen the supply of'a-ir until the fire dies down and no longersupplies an adequate quantity of .heat. l v I The grate'which I havedevised overcomes the aforesaid difficulties, provision being thereinmade not only for the removal of ashes and the simultaneous loosening ofthe fuel mass, but for rendering theclinkers accessible throughthefeeddoor of the furnace. These -and other advantages to be de rived from theuse of my. grate, will be un derstood by those who read the following.

positions on the grate. 7

description in connection withfithe accom panyingdrawings in which-1 1Figure '1 is a view of a furnace {Sh i front elevation parts beingbroken away ;;v

Figure 2 is a view of the grate lookingtowardvtlie front end thereof;-

Figure 3 is a vertical;longitudinal vi w of the furnace, parts beingbroken away;

Figure leis a sectional view of part-of the sifter showing one oftheagitating pins (in elevation, and I 1 r ,7

, Figure 5 is a fragmentary sectional View grateand the sifter. I a

I vThe furnace 1 may be of any usualtype, and said furnace is'providedwith a fire box: 2 within which-i s disposed the grate 3.

showing the sliding connectionbetween the l This igrate, which ispreferably semi-0y lindrical in form, contains-transversely arrangedgrate barsf' separated; by washers v5 of any desired thickness as may bedeten mined by the finenessof the fuel,"a nd these bars are-united by.tie rods 6 extending through aligned perforations of-said barsin.

,a'usu'al' manner. -The grate'is supported by two trunnions 7, 8,=respectively mounted in bearings 9, l0,arranged at the front and the back ofthe furnace, the trunnion Tbeing long enough to protrude "through thefront wall ofthe fire boxiwhereait is-s'quared to receive a suitableactuating handle.

The front platell of the grate,'i.s provided with spaced bars 12.,andthe back plate 13-of said grate, is likewise provided withspacedba-rs' 114, the tie rods 6 being extended-through both oftheseplates in or-' derto hold them securely in their respective j The grateisprovided, at per edges, with afllongitudinal side bar 15' havinganL1ndercut groove- 16, and these each of its bars are secured to thegratebyscrewsnll Associated: with the grate is a remoyable sifter l8 which,likethe grate, is preferably of semi-cylindrical shape, whereby thegrate and. the sifter constitute. a complete cylinder within which the,charge {of fuel may travel circumferentiall-y as the grate is revolvedoroscillated onsits trunnions to: thereby .agitate said charge and relieveit'of its ash con tent. During this operation the fuel charge will, by Igravitative action, continuously tumble down the rising wall of thedevice, thereby loosening the fuel to such extent as admit of a freeflow of air therethrough when the ash-sifting operation is completed andthe furnace resumes its normal operation. The clinkers which appear atthe surface of the mass of agitated fuel, may, if too large toeventually be sifted out with the ashes, be conveniently removed throughthe feeding orifice of the furnace which, as shown, extends above thetopof the grate a sufiicient distance to admit of the insertion andwithdrawal of the sifter which is adapted to be interlocked with thegrate in a removable manner. The sifter is open atthe ends, and affords,therefore, no obstruction to the insertion of an instrument through thefeeding orifice of the furnace by means of which the clinkers may betaken out;

The sifter includes front and rear bowed angle irons 19 each having ateach of its ends a foot 20 resting on and "secured to a slide bar 21that is provided with a male dovetail 22 loosely fitting the under-cutgroove of the corresponding side bar 15 to insure the easy withdrawal ofthe sifter after it has subserved its function, the foot and the slidebar being firmly united by 'machine screws 23. The sifter also includesa frame-work 24 of flat iron, suitably secured to the slide bars 21, anda longitudinal rib 25, which is fastened to the angle irons 19 and theframe-work 24 by rivets or other suitable devices.

Extending through holes in the rib 25, are depending and preferablypointed pins 26 arranged in a row, and each of these pins is providedwith a shoulder 27. A wiremesh screen is sustained by the frame work 24,the lower edges of said screen being retained by hook bolts 29 suitablyanchored in the angle irons or the frame-work of the sifter. The archedportion of the screen is held in position by the pins 26 which extendthrough said screen at several points.

The doors of the furnace are oppositely hinged, and are of such shape asto cover the feeding orifice of the furnace, which is of circular formto admit of access to both the Sifter and the grate, and each door iscut away, as shown, to permit of the protrusion of the trunnion 7.

The operation of a furnace embodying my invention is easily understoodand conducted. Thefire is started in the usual way, and combustion ofthe. fuel is allowed to proceed uninterruptedly until it is necessary toeliminate the accumulations of incombustible matter and add new fuel.When this necessity arises, the front doors of the furnace will beopened, and the Sifter will be in ser'ted over the grate, the maledovetailbeing engaged with-the under-cut groove at the of the sifter tothereby cause "said sifter to'become, iii effect, a part of the grateand to partake of all of the movements thereof. As soon as the union ofthese ele ments is thus established, the grate will be revolved oroscillated on its trunnions until the unconsumed fuel is freed of itsashes and small clinkers and both have escaped through the spacesbetween the grate bars or through the meshes of the screen of thesifter, and fallen into the ash-pit of the furnace. It will be foundthat a portion, at least, of the clinkers which are at first too largeto pass-between the grate bars or through the meshes of the screen,willbe broken up by the pins of the sifter into pi'ecessmall enough tobe sifted out with the ashes, and that, in consequence of this sub:division of such clinkers as may be disintegrated, only a few clinkerswill have to be removed through the furnace door. ;The pins,furthermore, greatly assist in the separation of the ashes and the fuel,since they are set close enough to themselves act as Sifters, and theyalso hold and carry with them considerable quantity of the fuel, therebyreducing the quantity of unburned lumps thereof which otherwise would bepresent on parts of the siftr screen and in- 7 terfere with the escapeof the ashes.

The grate and the Sifter are both capable of eliminating the ashes ofthe charge of fuel, but ordinarily the sifter will be utilized becauseit is especially adapted for the work.

When the fire has been cleaned in the manner above described, the gratewill be returned-to its normal pendent position, and the sifter removedthrough the front opening of the furnace. Fresh fuel may then besupplied, and combustion allowed to. proceed.

Having thus described my invention, what I claim is:

1. A grate comprising segmental end portions and intervening fuelsustaining bars, combined with a removable ar cuate and open-ended, ashsifter arranged to receive materials from said fuel-sustaining bars whensaid grate is inverted.

2. The combination with a furnace hav- 1 ing a revoluble grate, of alongitudinally removable sifter for said grate, the end of thecombustion chamber being provided with an opening to permit the sifterto be attached to thegrate and removed at will.

3. The combination with a combustion chamber having an opening in an endthereof, of arevoluble arcuate grate .Silbstantially aligned witlrsaidepening, and an sifter forsaid grate adapted tb belon; gitudinallyremoved from said grate through said end opening. v The combinationivit-h combustion chamber having an end "opening of a grate revolubly mointed' in combustion chania t. nd as t x. ea ers amenan opening andinterlocked with said grate.

5. The combination with a combustion chamber having an end opening, ofbearings for the trunnions of a revoluble grate, a revoluble gratemounted in said bearings, a sifter detachably. connected with saidgrate, and a closure for said end opening, saidend opening being of sucharea as to expose said grate and said sifter when said;

closure is removed from said opening.

v6. The combination with a grate, of a sifter having a sliding andinterlocking engagement with said grate.

7. The conibination with a rotary-grater; fjof a detachable*sifter-having. ga row of spaced pins extending parallel with the axison which saidgraterotates.' 1

8. The combination with an arcuate rev+ oluble grate having longitudinal'grooves'in its edges, 0f aremovable ash Sifter provided with slide barsat-its' sides'conforming to. 20 a and interlocking with said grooves;

In testimony whereof I aflix my signature.

JOHN HARTMANN. 7

